They're not doing it for money lost or gained. They're doing it bc they want every away ticket used and not bought/not attended. This is to discourage people from not showing up.Lack of common sense.
The funny thing is, how much could the club really be losing on these? I'd assume it's the worst with away games at Red Bulls. They only distribute a few hundred tickets. If they are losing $13/ticket you are talking a couple grand if 50% of fans don't show up. For away matches when only a handful of tickets are sold, you're probably talking in the hundreds of dollars lost. Over the course of the season there is no way they are losing any material amount of money doing this. Sometimes there is just a cost of doing business and this should be pocket change to an MLS club.